Pakistani news outlet, Dawn, cites Quetta senior police official Wazir Khan Nasir, who says the bomb appeared to target Shiite Muslims because of the neighborhood the attackers picked. Most of the victims are women with their children who were shopping for vegetables.

After the blast, enraged residents formed a huge crowd, and police and rescue workers couldn't initially get through to victims. The bomb was stashed on a motorcycle and parked next to a building; the building partially collapsed after the explosion, and there are reports that some people were trapped inside.

According to The Associated Press, there have been several attacks against Shiite Pakistanis in Baluchistan province, of which Quetta is the capital, over the past several months. Militant groups are active in the region.

On Jan. 10, attackers targeting the Shiite community in Quetta carried out two separate bombings, killing at least 119 people and wounding 121, according to the BBC. Relatives of the victims were so angry they would not bury their dead until they got promises of better security from provincial officials.

Update at 1:51 p.m.: Death Toll Rises

Police now say at least 63 people were killed in the bombing and another 180 were injured. A police official says the remote-control bomb had been strapped to a motorcycle, the BBC's Marianna Lawnsettle reports.